Disclosure summary
A flaw was found in OpenSSH. A malicious SSH server can exploit a double free vulnerability in the Diffie-Hellman Group Exchange (DH-GEX) client path. This occurs during FIPS (Federal Information Processing Standards) mode known-group validation when the client processes attacker-controlled DH-GEX group parameters. Successful exploitation leads to client-side process termination, resulting in a Denial of Service (DoS).
Source-reported weakness categories
CWE-415
Source-specific records & product guidance
Sources retain their own attribution and scoring. Follow the original record to confirm affected versions, fixed releases, and configuration conditions.
NIST National Vulnerability Database · NVD-CVE-2026-55653
Open original source · Updated Oct 06, 2026
Only CPE matches marked vulnerable=true are indexed. AND/OR platform conditions must be checked in the original NVD record.
| Vendor | Product / association | Version / bounds |
|---|---|---|
| openbsd | openssh | - |
| redhat | hardened_images | - |
| redhat | openshift_container_platform | 4.0 |
| redhat | enterprise_linux | 6.0 |
| redhat | enterprise_linux | 7.0 |
| redhat | enterprise_linux | 8.0 |
| redhat | enterprise_linux | 9.0 |
| redhat | enterprise_linux | 10.0 |
Original records & references
- NIST NVD record
- CVE Program record
- access.redhat.com
- access.redhat.com
- access.redhat.com
- access.redhat.com
- access.redhat.com
- access.redhat.com
- access.redhat.com
- access.redhat.com
- access.redhat.com — Vendor Advisory
- bugzilla.redhat.com — Exploit, Issue Tracking, Vendor Advisory
PUBLISHED 2026-06-23T00:17:36-04:00
MODIFIED 2026-10-06T23:16:59-04:00
INGESTED 2026-10-10T20:25:11-04:00